If you embrace healthy dietary recommendations, you’re probably consuming kefir and kimchi, which aid in digestion and promote immune function. But, recently the billion-dollar beauty industry has jumped on board too, and probiotics are in everything from cleansers to serums to sunscreens. Are probiotics really beneficial when rubbed on the skin?
The thinking behind topical probiotics begins with an understanding of how probiotics are helpful in the gut. Diets full of processed foods and chemicals can alter the acidity and balance of our natural gut bacteria. When the gut’s microbiome (the term for a habitat of all the helpful organisms living in our guts) is altered, inflammation ensues, digestion of nutrients slows, bacteria fail to fight off infectious pathogens, and gas and indigestion become the norm. Although consuming probiotics can help normalize an inflamed gut, we’re not yet sure if either eating or using them topically benefits the skin.
The skin microbiome is a complex habitat where over 1 billion resident organisms (bacteria, yeasts, viruses, and mites) live in a single square centimeter. These organisms work symbiotically to keep skin hydrated, protect against infectious organisms, and boost normal cellular turnover, promoting skin health. When this system is disrupted, skin disease or infection can occur. Overgrowth of a specific yeast is responsible for causing the redness and flaky skin on the scalp we call dandruff. And a recent study from UCLA suggested that a disruption of the skin’s microbiome predisposes to acne1.
There are many less controllable factors that can alter the skin microbiome, like age, gender, genetics, and geography. But, over-cleansing, not moisturizing, scrubbing, toning, and even wearing certain make-ups can also strip the skin of its normal residents, causing an imbalance in the microbiome. To cultivate a healthy skin microbiome, it’s best to avoid harsh synthetic soaps, fragrances, and abrasive toner. Using products with selenium, a natural mineral that supports skin health, ceramides and hyaluronic acid for natural moisture, and niacinamide to decrease redness may benefit skin health. Avoiding synthetic clothing that can harbor bacteria that are not native to the skin could also be helpful.
But back to probiotics. In theory, if these products help restore a healthy population of skin microbes and pH balance, they may be helpful in treating inflammatory diseases like acne, rosacea, and eczema. Although research in this area isn’t yet robust, early studies have suggested that adding a number of commensal types of bacteria, like Lactobacillus, ammonia-oxidizing, and nitrifying bacteria may successfully reestablish a healthy microbiome. Nitrobacter, which produces nitrate can protect against fungi and UV-induced skin damage. Lactobacillus can decrease inflammation, improve the skin’s immune system and also protect against UV rays. And Bifidobacterium breve B-3 helps increase skin hydration and barrier function.
As we learn more about the healthy composition of the skin’s microbiome, we will be able to better formulate products that are customized for certain conditions. For now, a trial of a topical probiotic may be an interesting experiment, especially if you suffer from an inflammatory skin condition like rosacea or acne, but data for specific products is still scant. Stay tuned because we’re watching this research carefully!
1. Barnard E et al. Sci Rep. 2016 Dec 21;6:39491.
